Abstract:

Objective To investigate the correlation of serum estrogen and progesterone levels and expression of estrogen and progesterone receptors in pelvic floor tissues with stress urinary incontinence (SUI) in late pregnancy. Methods Seventy-one pregnant primiparas undergoing vaginal delivery were divided into SUI group (n=33) and non-SUI group (n=38), and serum levels of estradiol (E2), estriol (E3) and progesterone (P) were detected at gestational week 36 to 40. Muscular tissue samples were obtained from the top of lateral incision of perineum from 20 cases in SUI group and 31 cases in non-SUI group after delivery, and pathohistological and ultrastructure observations were performed. Another 3 nonpregnant female patients with carcinoma of vulva or rectum cancer undergoing surgery were served as controls. The expression of estrogen receptor and progesterone receptor in pelvic floor tissues was detected by immunohistochemical staining. Results There was no significant difference in serum E2 and E3 between SUI group and non-SUI group (P＞0.05). The serum mass concentration of P in SUI group was significantly lower than that in non-SUI group [（184.7±48.2）μg/L vs （223.2±93.5）μg/L]（P＜0.05）. Pathohistological and ultrastructure observations revealed that there were vacuolar degeneration, filament alteration and edema in smooth muscle cells of deep pelvic floor. The expression of estrogen receptor and progesterone receptor in smooth muscle cells in non-SUI group was significantly higher than that in SUI group (P<0.05). There was no expression of estrogen receptor and progesterone receptor in skeletal muscle cells of pelvic floor. Conclusion Both estrogen and progesterone may protect the structure and function of pelvic floor in pregnant primiparas.

Key words: pregnancy, stress urinary incontinence, estrogen, progesterone, receptor